Variable throttle controls

ABSTRACT

A control adapted to be used in a motor vehicle for controlling the throttle valve from a pedal and having the capability of enabling the sensitivity of the throttle to be variably adjusted by the driver while driving. The control superimposes a variable amplitude sine wave function upon the conventional sensitivity relationship by modifying the movement of the pedal through a cam whose output is multiplied in a multiplying mechanism by a driver-selected factor and which result is added in a summarizer to the pedal movement to be transmitted to the throttle.

United States Patent [72] Inventors Raymond L. Garman 2,156,127 4/1939 Roberts..... 74/516 l-lastings-on-the-Hudson; 2,338,379 1/1944 Henke 74/516 Herbert Ziebolz, New York, NY. 2,917,943 12/ 1959 Vlannes 74/516 2; 3 1969 Primary Examiner-William F. ODea i45i P f nted A i- 27 1971 Assistant Examiner-Wesley S. Ratliffilr.

P Attorneys-Marshall J. Breen, Chester A. Williams, Jr. and [73] Assignee The Singer Company RobenE Smith New York, N.Y.

[54] VARIABLE THROTTLE CONTROLS 3 Clams 3 g Flgs' ABSTRACT: A control adapted to be used in a motor vehicle 74/516 for controlling the throttle valve from a pedal and having the [51] Int. Cl G05g 1/04, im f enabling the Sensitivity f the throttle to be G05g 1/00 variably adjusted by the driver while driving. The control su- Fleld 0f Sfil'ch perimposes a variable amplitude ine wave function upon the 74/516, 469 conventional sensitivity relationship by modifying the movement of the pedal through a cam whose output is multiplied in [56] Reierences C'ted multiplying mechanism by a driver-selected factor and UNITED STATES PATENTS which result is added in a Summarizer to the pedal movement 1,928,083 9/ 1933 Warren 74/516 to be transmitted to the throttle.

PATENTEUAFRZTIS?! 3576;140

sum 1 BF 2 MAX.

THROTTLE TRAVEL PEDAL TRAVEL MIN.

Fig 3 INVENTORS Raymond L. Garmun Herbert Ziebolz WITNESS= I 3 WQ'ATTORNEY SHEET 2 BF 2 PATENTED APR27 l9?! INVENTORS Raymond L. Garmcm Herbert Ziebolz ATTORNEY WITNESS= BACKGROUND OF THE INVENTION This invention relates to a variable transmission ratio throttle control and more particularly to a control between the acceleration pedal and the throttle valve in a motor vehicle which allows the driver while driving to adjust the rate at which the throttle opens relative to the depression of the pedal.

Conventional throttle control linkages provide substantially equal throttle opening increments for equal pedal travel, i.e., a straight line relationship between throttle opening and pedal travel. Such a relationship has heretofore been recognized to have certain disadvantages. At low speeds, the system is too sensitive for proper engine control. For example, it is difficult with such systems to obtain a smooth acceleration from a stationary position, or to effectively accomplish delicate lowspeed maneuvers such as parking. The prior art endeavored to decrease this sensitivity at low speeds by various linkage arrangements acting to open the throttle slowly during the initial throttle-opening positions and to open the throttle quickly upon further opening of the throttle. Thus, there was provided a low sensitivity at the low speeds and a high sensitivity at the high speeds. Sensitivity is here defined as the incremental change of throttle opening to the incremental change in pedal travel.

A problem with these prior art throttle controls is their high sensitivity at high speeds. It bwomes necessary for a driver to closely and continuously monitor his speedometer when driving at or close to the legal limit of speed. This problem can be critical when the driver has been driving for a long time and fatigue is setting in. This constant monitoring of the speedometer distracts his attention from the trafiic pattern, thus creating a safety problem. What would be desirable from this safety standpoint is a control having less sensitivity at the higher speeds. However, with such a control another safety problem arises; that of having sufficient acceleration potential to safely pass another vehicle while driving near the legal speed limit, i.e., a high sensitivity system is desirable for passing under such conditions.

SUMMARY OF THE INVENTION The present invention recognizes these problems and provides a mechanism which enables the driver to select at any speed of the vehicle the sensitivity which gives him the best control of the vehicle. In short, it enables the sensitivity of the throttle to be varied by the driver while driving. The mechanism can be simply packaged in a black box" configuration and inserted in the throttle linkage of present vehicles by merely replacing a part of the present linkage between the pedal and the throttle. This is done without changing the available stroke of the pedal or the maximum or minimum opening of the throttle. There is thus no decrease in the space available within the cab to the driver or the range of speeds available to him.

It is, therefore, an object of the present invention to provide a variable transmission throttle control in which the sensitivity of the throttle is selectively adjustable at the discretion of the driver while driving in order to meet any of the drivers requirements at any given speed condition without afiecting at the same time the range of speeds available to the driver.

Another object of this invention is to provide a device adapted to be installed between the accelerator foot pedal and the carburetor of a motor vehicle which allows the driver to selectively change the sensitivity of the throttle at any point of the foot pedal stroke.

To these ends, the present invention contemplates a device which can be packaged in a small container that can be easily installed in existing vehicles and which comprises means connecting the foot pedal linkage to a summarizer and to an S- shape function generator. Operatively connected to the function generator to obtain an input therefrom, and to a driveroperated selection knob for a second! input, is a multiplying unit which produces at its output a movement proportional to the product of the input movements. This output movement is transmitted to the summarizer where it is added to the movement inserted by said means connecting the pedal linkage to the summarizer. The output of the Summarizer is connected to the throttle linkage to vary the opening of the throttle valve.

In the preferred form of the invention the function generator comprises a biased cam shaped to generate a sine wave. The multiplying unit consists of a mechanical linkage multiplier comprising a series of levers, and the summarizer is of the simple mechanical whiffletree type.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2 is a diagrammatic illustration of the variable throttle I control of the present invention and showing the simple packaging required therefor;

FIG. 3 is a graphical representation of throttle movement relative to pedal movement for a throttle control system incorporating the mechanism of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 of the drawing, there is shown the general arrangement of the sensitivity control as it would be installed in a vehicle having a foot pedal 10 connected to the foot pedal linkage comprising levers 11 and 12. Lever 11 is pivotally mounted as at 13 to, for example, the fire wall of the vehicle in the usual manner. Pin connected to lever 12 at 14 is an arm 15 of bellcrank 16 in the variable throttle control unit, designated generally as 17, and which subsequently will be more fully described.

A driver-influenced control knob lid is mounted in a slot 19 on the dashboard of the vehicle for adjustably selecting the desired throttle sensitivity. Indicia 20 may be arranged along the slot for indicating the selected sensitivity, e.g., high, normal, low, etc. Fixed to the knob 18 is an arm 21 which is pivotally mounted at 22 on the tire wall on the dashboard and is pin-connected at 23 to lever 24. The lever 24 is further pinconnected at 25 to a rod 26 which applies the sensitivity adjustment to an input terminal 27 of a multiplying mechanism indicated generally as 28 and which will be more fully described as this description proceeds.

The motions applied to the variable throttle control unit 17 are therein combined by means to be described and an output is effected at lever 29. A lever 30 is pin-connected at one end to lever 29 and at its other end to one arm 31 of a bellcrank 32 pivoted at 33. The other arm M of bellcrank 32 is connected to one end of a rod 35, the other end of which is operatively connected to throttle valve 36 within a carburetor 37.

Within the control unit 17, the bellcrank 16 is pivotally mounted at 3% on a wall 39 of housing to and its second arm 15' is pin-connected to a rod 41. Movement of arm 15 applies movement within the unit 17 in two paths, the first of which, includes arm 15' and rod 41. The second path will be described in turn. Pin-connected to rod 41 is a cam 42 pivotally connected at 43 to the wall 39. The surface of the cam 42 is contoured so that as the cam is given a movement about pivot 43 by rod 41 an S-shaped function, preferably a sine function, is generated by movement of a cam follower 44. It is understood that the cam 42 may be contoured such that a reverse S-shaped function is obtained without departing from this invention. The cam follower M is pin-connected to a rod 45 which in turn is pivotally mounted at 16 on the wall 39. A spring 47, connected at one end to rod 45 and at its second end to the wall 39, biases the rod 15 toward cam 42 to thus maintain the cam follower 44 always in contact with the cam. It is thus clear that a movement of the foot pedal llil biases the cam 62 about pivot $3 to generate a movement of the follower which depends on the amount of such bias and, hence, foot pedal depression. The effect of the movement generated by the cam will he clarified presently with regard to Fit]. 3.

.lournaled at aid on the follower id so as to move therewith is a rod 49 which is further pin-connected to a first input terminal S of the multiplying mechanism 28.

The preferred multiplying mechanism of this invention, whose function will subsequently be clarified, is of the simple lever type, although any form of multiplying means, such as a l-leusinger gear, may be utilized. The disclosed multiplying mechanism is well known and by itself forms no part of the present invention. The mechanism 253 comprises a lever 51 one end of which is pivotally mounted at 52 on the wall 39, and the other end of which is pin-connected at 50 to the rod 49 and to one end of lever 53. The second end of lever 53 is pin-conn at 554 to one end of lever 55 whose other end is pin-connected at $6 to an arm 57 of bellcranlc The bellcrank 58 is pivotally mounted at 59 and its second arm as having an output terminal till forms the output of the multiplying mechanism, tenninal 27 forms a second input terminal to the multiplying mechanism 2d. Pin-connected at 27 to rod 26 is one end of a lever 62 whose other end is pivotally mounted at 63 to the wall 39. Also, pin-connected at terminal 27 is a lever 64 whose second end is also pin-connected at 54% to levers 53 and 55. Movements applied to input terminals Ell and 27 are multiplied by the combination of levers to produce a movement at output terminal 61 which is proportional to the product of the two input movements. A lever 65 is pin-connected at 611 to receive and transmit the movement of the multiplier to one input terminal as of a summation means, generally indicated as 67, which will now be described.

The summation means 67 which is of the simple whiffletree type comprises a lever ed to which a second lever so is pinconnected at 70. Movement is imparted to the summarizer at the terminal lift by lever 65 and at a second terminal 7i, by a lever 72 pin-connected at 71 to lever d3. The lever 72 forms the second path of movement through the unit 17 and is further pin-connected at 73 to the arm N of bellcrank lid. The summarizer produces at an output terminal 74 a movement that is proportional to the sum of the movements applied at terminals as and 71. Pin-connected to lever as at terminal 74 is the lever 29, which is pivotally connected at 7 to the wall 39. It is noted that although a whiftletree summation device is disclosed, any of the other well-known types of adders may be used.

It is apparent from the above description of the apparatus that when the knob 38 is moved to a selected indicia, a movement is applied to terminal 27 of the multiplying mechanism 28 that modifies the pedal/cam-generated movement applied to terminal 5417 of the mechanism and the resulting movement is applied to the Summarizer 67 where it is added to the pedalgenerated movement of lever 72 to produce a movement that varies the opening of the throttle valve 36.

OPERATION The operation of a variable throttle control system incorporating the present invention will now be described with reference to FIG. 3 in which throttle travel ormovement is plotted against pedal travel or movement, i.e., the slope at any point on a curve in this graph is the sensitivity of the throttle n: at that point. Conventional throttle control systems having a straight line relationship may be used as a starting point for this discussion, such a system is shown by line 76. It should be noted that this line may be modified, as by some prior art devices, to have a reduced slope at the low end and an increased slope at the higher end, but the discussion that follows includes this modification of line 76, it only being used as a reference line upon which the present invention is super-imposed. The minimum opening of the throttle is designated as MIN, the maximum opening as MAX. The present invention superimposes a sine wave 77 over the curve 76 such that the full stroke of the throttle as designated by the points MIN. and MAX. is preserved. The wave is preferably a sine wave but may be any S-shaped wave, having a varying amplitude including an inverted S-shaped wave, and it should have positive and negative excursions relative to the line 76. The point of intersection A of the curves 76 and 77 is shown as being symmetrically between MIN. and MAX, but may be anywhere along line 76 without varying from the concept of this invention. The sine wave is superimposed by means of the cam d2, but again this invention is not limited to a cam, as a crank or a gear sine generator may be used instead. it is seen from the curve 77 that at the low and high ends of pedal travel a small slope and hence sensitivity is chested while at the intermediate positions of pedal travel there is a large slope mid hence a high sensitivity in the system. The present invention furthermore allows a complete variation in the desired sensitivity by means of the selection knob 19 and the multiplication mechanism 28 which effect an adjustable amplitude of the curve 77. In FIG. 3 the maximum variation of the amplitude is shown by curve 78 which is a mirror image of curve 77 about curve 76, such that the positive excursions of curve 77 relative to line 76 become negative excursions of curve 78 relative to line 76 and the negative excursions of curve 77 relative to line 76 become positive excursions of curve 785 relative to line 76. This is effected by a multiplication factor of minus one inserted into multiplier 28. It is noted that in curve 73, a high sensitivity is obtained at the low and high ends of pedal travel, while at the intermediate positions of pedal travel, a low sensitivity is effected. The area between the curves 77 and 78 defines the operating range of the present invention and any curve between these extremes, e.g., 79 or $0, may be chosen as an operating curve. Moreover, by proper manipulation of the control knob iii, the driver may shiit, at any time, from one operating curve to another so as to select the sensitivity of the throttle that suits him at that time.

We claim:

I. in a motor vehicle having a propulsion system including a throttle valve operated by a manually engageable foot pedal, a control for selectively varying the sensitivity of the throttle valve, said control comprising:

a. first means operatively connected to the pedal for predetermined movement therewith when said pedal is selectively moved,

[7. generator means operatively biased by said first means for generating a movement which produces a predetermined relationship between movements of said valve and movements of said pedal,

c. multiplying means having two input terminals and an output terminal for modifying the amplitude of said generated movement,

d. means responsive to operation of said generator means for applying to a first of said input terminals the movement generated by the generator means,

e. manually adjustable means for applying to the second of said input tenninals a selectively controlled sensitivity factor such that a movement is produced at the output terminal which is proportional to the product of the movements at said two input terminals,

f. summation means operatively connected with said output terminal and with said first means for producing a movement which is proportional to the sum of the movements applied thereto, and

g. means operatively connecting said summation means to the throttle valve for varying the opening of said valve by the movement produced by said summation means.

2. The combination of claim 1 wherein said generator means comprises a cam biased to be moved by said first means and said means for applying movement to said first of said input terminals comprises a follower biased to remain always in contact with said cam.

3. ln a motor vehicle having a throttle operating system including a throttle valve operably connected by linkage to a foot pedal and having a fixed relationship between throttle travel and pedal travel such that a graphical representation of said relationship between the limits of maximum opening of the throttle valve at maximum pedal depression and minimum opening of the throttle valve at zero pedal depression is a single line, the improvement comprising a control mounted in said linkage between said pedal and said throttle, said control including means for changing the relationship between throttle travel and pedal travel such that in said graphical representation there is superimposed upon said line between said limits a first variable amplitude curve having positive and negative excursions relative to said line, said control furtherincluding means for modifying said last-named means such that in said graphical representation said excursions of said superimposed curve are inverted about said line to obtain a second variable amplitude curve, said last-named means being manually operable while said vehicle is in operation for selectively operating in the area represented between said first and second curve. 

1. In a motor vehicle having a propulsion system including a throttle valve operated by a manually engageable foot pedal, a control for selectively varying the sensitivity of the throttle valve, said control comprising: a. first means operatively connected to the pedal for predEtermined movement therewith when said pedal is selectively moved, b. generator means operatively biased by said first means for generating a movement which produces a predetermined relationship between movements of said valve and movements of said pedal, c. multiplying means having two input terminals and an output terminal for modifying the amplitude of said generated movement, d. means responsive to operation of said generator means for applying to a first of said input terminals the movement generated by the generator means, e. manually adjustable means for applying to the second of said input terminals a selectively controlled sensitivity factor such that a movement is produced at the output terminal which is proportional to the product of the movements at said two input terminals, f. summation means operatively connected with said output terminal and with said first means for producing a movement which is proportional to the sum of the movements applied thereto, and g. means operatively connecting said summation means to the throttle valve for varying the opening of said valve by the movement produced by said summation means.
 2. The combination of claim 1 wherein said generator means comprises a cam biased to be moved by said first means and said means for applying movement to said first of said input terminals comprises a follower biased to remain always in contact with said cam.
 3. In a motor vehicle having a throttle operating system including a throttle valve operably connected by linkage to a foot pedal and having a fixed relationship between throttle travel and pedal travel such that a graphical representation of said relationship between the limits of maximum opening of the throttle valve at maximum pedal depression and minimum opening of the throttle valve at zero pedal depression is a single line, the improvement comprising a control mounted in said linkage between said pedal and said throttle, said control including means for changing the relationship between throttle travel and pedal travel such that in said graphical representation there is superimposed upon said line between said limits a first variable amplitude curve having positive and negative excursions relative to said line, said control further including means for modifying said last-named means such that in said graphical representation said excursions of said superimposed curve are inverted about said line to obtain a second variable amplitude curve, said last-named means being manually operable while said vehicle is in operation for selectively operating in the area represented between said first and second curve. 